Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

This study was carried out to estimate total catches extracted from the offshore areas of northeastern Brazil by recreational fishers from offshore operations, daily activities, and fishing competitions. It also aimed at providing a first estimate of expenditure by anglers in the region. The basis for this analysis was the data supplied by the only offshore fishing operator established in Paraíba State. The available logbooks allowed for the first estimate of total catches by anglers in Paraíba State, which was extrapolated to the entire region using information provided in a database of recreational fishers’ licenses. By combining these data with catch data from fishing competitions, we were able to estimate that a peak of about 90 t was extracted in 2011. This catch is low when compared with commercial catches, but the associated economic impacts, assessed via the expenditure by recreational fishers at US$1.5 million in 2014, is high. Moreover, catches are concentrated mainly on a small number of species, mostly Thunnus spp. and Seriola spp. in waters off Paraíba State. No information is available on the current status of these amberjacks (Seriola spp.). However, some of the snappers (Fam. Lutjanidae) included in the top species caught by recreational fishers are considered overexploited in the region.

The present study provides new documented cases of abnormalities on chitons (hypomerism and coalescence of shell plates), in addition to four new cases on keyhole limpets (closed apical opening), and one new teratologic case on internal organs in octopuses (missing gill). We assess the frequency of these abnormalities and discuss about its possible environmental, mechanic and genetic causes. Several of these findings represent the first of these cases reported in South Pacific Ocean.

Courtship and mating behavior are important life cycle aspects of marine turtles not easily observed by researchers. A pair of loggerhead sea turtles (Caretta caretta) was documented circling, attempting and successfully mounting in the Gulf of Ulloa, Mexico. This type of activity is part of an already described courtship and mating behavior for other sea turtle species; however, this is the first report of open-ocean courtship and mating behavior by loggerheads in the Northern Mexican Pacific Ocean.

The effect of five diets with different crude protein levels (27, 33, 38, 43, and 48%) on growth and survival of Macrobrachium americanum prawns was determined. Optimum dietary protein level was also calculated. Specimens were collected in the Coyuca River, Guerrero, Mexico, and classified into seven weight groups with 0.67 g intervals amplitude. Five diets with different levels of crude protein were formulated and supplied to individuals of the seven weight groups as an experimental treatment. Weight gain percentage (WG%), specific growth rate (SGR), food intake (FI), protein intake (PI), protein efficiency ratio (PER), food conversion ratio (FCR) and survival rate (SR) were calculated weekly along the 70 days experiment. A quadratic model was fitted to weekly mean weight gain and to WG% rates data to estimate protein requirement for every week of the experiment and weight group. A mortality model was also fitted to mortality data to compare mortality trend among the different experimental diets. 33% protein level resulted in the best treatment because of the parameters calculated, cost to produce and survival trend. Weekly optimum level of protein calculus varied on a range from 39.4 to 43.3% and optimal crude protein percentage for the seven weight ranges was between 49% for smaller prawns (0.248-0.918 g) and 35.7% for the larger prawns (4.271-4.940 g). Thus, it is recommended juvenile feeding prawns with different crude protein levels while the culture time elapses to achieve the maximum weight gain.

The effect of different proteins and lipids levels on antioxidant response of superoxide dismutase (SOD) was tested in muscle, hepatopancreas and whole-body tissues of cauque river prawn Macrobrachium americanum juvenile. Six diets with two crude protein (35 and 40% diet) and three lipid levels (6, 10, and 14% diet) were tested for juveniles in a factorial manner (3×2), to provide six different dietary. Juvenile prawns (0.22 ± 0.03 g) were randomly placed in 18 plastic tanks (160 L), at a density of 15 juveniles per tank (3 tank replicates/treatment). The assay lasted 60 days. SOD activity was significantly different in muscle, hepatopancreas and whole body depending on proteins and lipids levels in the diet. Results indicate that the diet containing 35% protein and 10% lipid provided adequately to while preventing diet-induced oxidative stress and protecting the integrity of the antioxidant response of SOD.

Due to the presence of pollutants in aquatic systems, this research aims to analyze toxicity levels of Faena Clásico® , Asuntol® , sodium hypochlorite and diesel on Macrobrachium tenellum juveniles. For the purpose of this study, specimens from 2 to 4 cm in length were used. For glyphosate, hypochlorite and coumaphos bio-assays, a total of 8 individuals were placed per experimental unit, however, only 5 individuals were placed for diesel. Dead individuals were counted at the end of 24 h of exposure. All bioassays were performed in quintuplicate plus a negative control. The mean lethal concentration (LC50) was calculated by a Probit analysis and standard error. The mean lethal concentrations obtained are given at 6 h of exposure for 16 mL L-1 of diesel aqueous extract; and 24 h of exposure, solutions of Asuntol® 6 mg L-1, Classic Faena® 32 mg L-1 and sodium hypochlorite 59 mg L-1. Results show that the different chemicals assessed generate harmful damage to M. tenellum, since agrochemical compounds can cause alterations in the composition of ecosystems, reducing biodiversity in a temporarily or permanently manner.

The present study evaluates the potential of the house fly larvae (Musca domestica) as a protein alternative in the feeding of prawns (Macrobrachium tenellum). Three feeds were used to evaluate the following response variables: growth rate, survival rate, feed conversion ratio and protein efficiency ratio. The first feed (T1) was a meal obtained after process fly larvae produced in a controlled environment, the second one (T2) was an experimental formulated feed based on the meal obtained, and the third one (T3) was a commercial feed. The feeds were supplied to 216 individuals of M. tenellum, with an initial weight of 0.897 ± 0.007 g for a 60 days period. After 30 days, the experiment results showed that T2 presented significant differences in promoting the growth and survival of M. tenellum over the other treatments. However, at the conclusion of the study, an improvement was observed for T3 culminating with no significant differences for T2, which suggests that the domestic fly larvae possess nutritional characteristics that make viable the incorporation as a protein source in the formulation of a feed for Macrobrachium tellenum.

The San Pedro-Mezquital River basin in Nayarit, Mexico has the majority of freshwater prawns of the genus Macrobrachium reported for the Mexican Pacific coast. Six species of freshwater shrimp are reported Macrobrachium americanum, M. occidentale, M. digueti, M. michoacanus, M. hobbsi and M. tenellum. The higher richness and diversity of freshwater prawns are found on the coastal plain. The presence of prawns in relation to the altitudinal gradient is discussed.